title: Site-specific chemical modification of antibody fragments using traceless cleavable linkers.
abstract: Antibody-drug conjugates (ADCs) are promising agents for the selective delivery of cytotoxic drugs to specific cells (for example, tumors). In this protocol, we describe two strategies for the precise modification at engineered C- or N-terminal cysteines of antibodies in IgG, diabody and small immunoprotein (SIP) formats that yield homogenous ADCs. In this protocol, cemadotin derivatives are used as model drugs, as these agents have a potent cytotoxic activity and are easy to synthesize. However, other drugs with similar functional groups could be considered. In the first approach, a cemadotin derivative containing a sulfhydryl group results in a mixed disulfide linkage. In the second approach, a cemadotin derivative containing an aldehyde group is joined via a thiazolidine linkage. The procedures outlined are robust, enabling the preparation of ADCs with a defined number of drugs per antibody in a time frame between 7 and 24 h.
authors.affiliation: 1] Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology (ETH Zürich), Zürich, Switzerland. [2] Department of Chemistry, University of Cambridge, Cambridge, UK. [3] Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal.
authors.forename: Gonçalo J L
authors.initials: GJ
authors.lastname: Bernardes
authors.forename: Martina
authors.initials: M
authors.lastname: Steiner
authors.forename: Isabelle
authors.initials: I
authors.lastname: Hartmann
authors.forename: Dario
authors.initials: D
authors.lastname: Neri
authors.forename: Giulio
authors.initials: G
authors.lastname: Casi
mesh_terms: D003545:Cysteine / Q000737:chemistry*; D003603:Cytotoxins / Q000737:chemistry* / Q000627:therapeutic use; D016503:Drug Delivery Systems / Q000379:methods; D007128:Immunoglobulin Fragments / Q000737:chemistry* / Q000627:therapeutic use; D007162:Immunoproteins / Q000737:chemistry; D009842:Oligopeptides / Q000737:chemistry; D015202:Protein Engineering / Q000379:methods*; D053778:Thiazolidines / Q000737:chemistry
chemical_list: D003603:Cytotoxins; D007128:Immunoglobulin Fragments; D007162:Immunoproteins; D009842:Oligopeptides; D053778:Thiazolidines; C094621:cemadotin; D003545:Cysteine